1. Field of the Invention
The present invention relates to a broadband wireless communication system. More particularly, the present invention relates to an apparatus and method for notifying of a change or non-change of system control information in a broadband wireless communication system.
2. Description of the Related Art
A mobile communication system is evolving beyond a voice-centric communication system to provide a variety of services such as broadcasting, a multimedia video, a multimedia message, etc. Examples of this next generation communication system include an Institute of Electrical and Electronics Engineers (IEEE) 802.16e system, a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system, an IEEE 802.20 system, an Ultra Mobile Broadband (UMB) system, and an IEEE 802.16m system, etc.
To support a high data transmission speed in the next generation mobile communication system, a variety of transmission techniques such as the use of a multiple antenna system, Hybrid Automatic Repeat reQuest (HARQ), Adaptive Modulation and Coding (AMC), etc. are being introduced. In order for these transmission techniques to be managed, a Base Station (BS) has to transmit a significant amount of system control information to a plurality of user Mobile Stations (MSs). The system control information includes network and cell information that a user MS has to be aware of to perform mobile communication within a cell, for example, bandwidth information of the cell, configuration information of a physical channel, information of a parameter, etc. of an upper layer, etc., and information on a variety of transmission techniques supported in the cell, for example, number of transmit antennas, information on a multiple antenna, HARQ related information, modulation scheme information, etc.
In order for an MS to determine validity of stored system control information, a change counter for the system control information is transmitted. That is, if a change counter is received from a BS, an MS performs a comparison with a change counter that the MS itself knows. If the comparison result is that the known change counter is the same as the received change counter, the MS determines that system control information previously received and stored is valid. On the other hand, if the known change counter and the received change counter are different from each other, the MS receives new system control information. As a result, the MS may avoid attempting to decode repeated system control information.
However, because system control information includes information related to a system, it is rare that the system control information is changed while service is being provided. Thus, it is inefficient to transmit an information bit, i.e, a change counter for informing of change or non-change every frame in order to inform of a change of the system control information. In addition, the system control information includes information used for data transmission/reception, and includes information for supplementary service such as broadcasting related information, etc. Therefore, each item of information is different during the time required to update significance and information, etc. Thus, there is a need for an alternative for, by efficiently designing a transmission/reception scheme of system control information, solving the aforementioned problems and increasing system capacity in a next-generation wireless communication system.